[en] The integral expressions for spectral-angular and spectral distributions of the radiation power of charged particle systems moving on an arbitrary trajectory in nonabsorbable isotropic medium and in vacuum are obtained using Lorentz's self-action method. In this method proper electromagnetic field acting on the electron is defined as a semidifference between retarded and advanced potentials (Dirac, 1938). It is shown which redistribution effects in energy of the radiation spectrum of the studied system are caused by the coherent factor. The power spectra of Cherenkov, synchrotron and synchrotron-Cherenkov radiation are obtained for the system of electrons moving in a spiral. We have established that the radiation spectrum of the system of electrons moving in a circle in this medium is discrete. The Doppler effect causes the appearance of new harmonics in the radiation spectrum of the system of electrons moving in a spiral. These harmonics form the regions of a continuous radiation spectrum. (author)